Agricultural combines are well known in the art. They are available in various designs and models to perform the basic functions of harvesting and threshing of crop materials. A typical combine includes a crop harvesting apparatus which reaps planted grain stalks. An infeed mechanism arranged at the forward end of the combine operates in combination with the harvesting apparatus and feeds the grain stalks to a separating apparatus. The separating apparatus acts on the crop materials to thresh and separate grain from material other than grain.
A typical rotary combine has a separating apparatus that includes an axially elongated foraminous casing or cage that surrounds a rotor. Between the upstream and downstream ends of the separating apparatus, the crop materials are threshed several times repeatedly, but gently, as it spirals around the single large diameter rotor and passes through the threshing cage. Suitable instrumentalities on the rotor cooperate with an axially elongated threshing section on the lower portion of the casing to thresh the crop materials such that most of the grain will be separated and propelled downwardly through the threshing section. The threshing section of the casing or cage is comprised, at least in part, by a series of side-by-side perforated concaves. Each concave extends in partial circumferential relation relative to the rotor and defines an arcuate section in the lower region of the casing. Each of the concaves are supported for movement toward and away from the rotor.
The spacing between the rotor and concaves must be adjusted for different crops and different conditions. Various forms of concave adjusting devices for setting the clearance between the concave and rotor are known in the art. One form of concave adjusting device involves the use of shims to modify the clearance between the concaves and the rotor. Another form of adjusting device is shown in U.S. Pat. No. 3,871,384 to R. A. Depauw et al. Both of these known concave adjusting mechanisms involve time consuming manual processes for adjusting the clearance between the concaves and the rotor.
During operation of the combine, there are occasions when the continual flow of crop material through the rotor assembly becomes hindered or even blocked. To return the rotor assembly to working order, the operator must move the concaves away from the rotor to the fullest extent possible to provide adequate clearance for the problematic blockage to move through the rotor assembly. Thereafter, the concaves need to be returned to their operative position relative to the rotor assembly to continue the combine operation.
As will be appreciated, each of the concaves defining the threshing section of the rotor assembly is of substantial weight. Moreover, the threshing area of a combine has relatively tight space constraints therewithin. Thus, manual adjustment of the concaves relative to the rotor can be a time-consuming and tedious process. Of course, while the concaves are being adjusted relative to the rotor, the combine is ineffective. During a crop harvesting operation, time is a premium concern and, therefore, downtime for the combine should be minimized.
Thus, there is a need and a desire for a combine adjusting mechanism that promotes quick and easy adjustment of the concaves relative to the rotor.